Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Summary of Significant Accounting Policies [Abstract]

Supplemental Disclosure of Cash Flow Information

	Year ended December 31,
	2020		2019		2018
Non-cash transactions:
Accruals for capital expenditures	$	231	$	592	$	412
Cash paid for interest and income taxes:
Interest (1)	$	298	$	248	$	205
Income taxes, net of refunds received	$	220	$	474	$	567

(1)Included in this amount are approximately $58 million, $54 million and $49 million of interest costs that were capitalized as part of property, plant and equipment, net of accumulated depreciation, in 2020, 2019 and 2018, respectively.

Useful Life of Equipment

Asset type	Range of useful life
Computer hardware and software	3 to 7 Year
Manufacturing equipment	2 to 15 Year
Furniture and fixtures	5 to 10 Year
Transportation equipment	3 to 20 Year